DORI
= 0.9 isosurfaces for (a) water dimer, (b) ammonia dimer,
(c) methane dimer, (d) formic acid dimer, (e) π-stacked benzene
dimer, (f) T-shaped benzene dimer, (g) π-stacked adenine–thymine,
(h) hydrogen bonded adenine–thymine. Isosurfaces are color-coded
with sgn(λ2)ρ(r) in the range from −0.02 au (red) to 0.02 au (blue).